1. Field of the Invention
The present invention relates to a method and an apparatus for recording a user's table-of-contents (hereinafter, referred to as "UTOC") concerning the record of program data In lead-in areas of optical discs when the program data is recorded on erasable and rewritable-type optical discs.
2. Description of the Prior Art
In general, optical discs can be divided into discs for an exclusive use of reproduction, discs for an use of an additional record, and discs for an use of erasing and rewriting according to functions and uses thereof. The disc for exclusive use of reproduction is a recording medium which can only reproduce information stored in the optical disc such as a compact disc, a compact disc-read only memory (CD-ROM), a video disc and so on. Once a user records the information onto the disc for use of an additional record, the user can repeatedly read the recorded information from the disc, but cannot erase the recorded information so as to rewrite it onto the disc.
The user can erase and rewrite recorded information from and onto the disc for use of erasing and rewriting as well as the record and reproduction of the information. Optical discs which are adopted to a digital versatile disc recorder (hereinafter, referred to as "DVDR") are those for use of erasing and rewriting.
In general, the DVDR needs position information which indicates each of track numbers of the optical disc and, start and stop positions of each of tracks in order to reproduce data which is recorded on the tracks of the optical disc. Original position information is recorded in a lead-in area of the optical disc as a table-of-contents (hereinafter, referred to as a "TOC") by manufacturers of the optical discs.
When the DVDR system is directly connected to an external apparatus, e.g., a program data source apparatus such as video cassette recorder and a television set, the user can record program data supplied from the external apparatus onto a predetermined section of the optical disc.
When new program data is recorded onto a predetermined section of the optical disc for use of erasing and rewriting, the position information concerning the data which is previously recorded on the optical disc changes. Accordingly, when the data is additionally recorded onto the optical disc, the position information which indicates the track number, and the start and stop positions of the track concerning newly recorded program data have to be additionally recorded onto the optical disc in order to randomly reproduce the information which is recorded on the optical disc. At this time, the additionally-recorded position information is recorded in the form of the UTOC in the lead-in area of the optical disc. Also, the DVDR has to update alternation particulars concerning the position information of the data which is generated by recording the new program data in the UTOC.
U.S. Pat. No. 5,432,768 (granted to Shigeo Terashima et al.) entitled "METHOD AND APPARATUS FOR DATA MANAGEMENT IN OPTICAL RECORDING MEDIUM" discloses a method and apparatus for recording the above-described UTOC. According to the above method and apparatus, a TOC area includes an absolute address of a record position of each information which is recorded on an information record area. A display section schematically and independently indicates recording and non-recording areas according to the absolute address of the record position of each information piece which is recorded on the TOC area. When new information is recorded into the position of the information record area in which different information has been previously recorded, an alarm section warns the user by referring to the TOC area that different information is recorded in the position of the optical disc.
However, the above-described prior art discloses the method and apparatus which records information units having desired lengths in the information record area, and which records, onto the TOC area, contents information which indicates the absolute address of each of the information units. Accordingly, in the prior art, a method and an apparatus which reflect onto the UTOC the track number of data and the alternation particulars of the position information of each of the previous tracks caused by the additional recording of the program data, is not disclosed.